<!doctype html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport"
        content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
    <title>方式三</title>
    <link rel="stylesheet" href="bootstrap/bootstrap.min.css">
    <script src="js/jquery.min.js"></script>
    <script src="bootstrap/bootstrap.min.js"></script>
</head>
<body>
    <ul class="nav nav-tabs visible-lg">
        <li role="presentation" class="active"><a href="#">Home</a></li>
        <li role="presentation"><a href="#">Profile</a></li>
        <li role="presentation"><a href="#">Messages</a></li>
    </ul>
    <div class="dropdown visible-xs">
        <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown"
            aria-haspopup="true" aria-expanded="true">
            Dropdown
            <span class="caret"></span>
        </button>
        <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
            <li><a href="#">Home</a></li>
            <li><a href="#">Profile</a></li>
            <li><a href="#">Messages</a></li>
        </ul>
    </div>
</body>

</html>